Ply-bonding method, apparatus and product

ABSTRACT

Ply-bonding method, apparatus, and product wherein at least two webs are advanced between a notched, beveled wheel and two beveled anvil surfaces to subject the webs to a pair of intermittent angled compressive forces.

I United States Patent 1 [111 3,834,286

Nystrand Sept. 10, 197 4 [5 1 PLY-BONDING METHOD, APPARATUS AND 2,935,002 3/1960 Robinson, Jr 93/1.l PRODUCT 3,323,983 6/1967 Palmer et al 93/l.l X 3,603,216 9/1971 Johnson 93/l.l X [75] Inventor: Ernst Daniel Nystrand, Green Bay,

W- ls 0 Primary ExaminerAndrew R. Juhasz Asslgneei P" Convemng Machm'e Assistant ExaminerLeon Gilden p y Green y Attorney, Agent, or FirmDawson, Tilton, Fallon & 22 Filed: 011.3, 1972 Lungmus [21] Appl. No.: 294,628

[57] ABSTRACT CCll. plybonding method, apparatus, and product wherein 58 d 29/470 at least two webs are advanced between a notched, 1 0 {13/116 beveled wheel and two beveled anvil surfaces to subject the webs to a pair of intermittent angled compres- [56] References Cited Swe forces UNITED STATES PATENTS 5 Claims, 10 Drawing Figures 1,657,591 l/l928 Schlender 93/l.l

PAIENIEB SEP 1 0 I924 Y 3.834.286 ,SHEU 10? 2 I sum. 2 or 2 PATENTED 35?! FLY-BONDING METHOD, APPARATUS AND PRODUCT BACKGROUND AND SUMMARY OF INVENTION For many years, workers in the paper art have sought a reliable, inexpensive way of bonding sheets or plies together. In fact, this is not limited to paper per se, but extends to a wide variety of flexible webs. A review of the art in the US. Patent Office Sub-Classes 83-12 and 93-1..l reveals that toothed wheels have been used in the past for selectively compressing plies together. For example, in US. Pat. No. 1,657,591, two wheels with the teeth thereof interengaged are employed for binding paper sheets. In U.S. Pat. No. 3,074,324 a toothed wheel operates against a solid roll for the same purpose.

There are a number of drawbacks characteristic of the prior art which are not present in the instant invention. According to the instant invention, the elongated, superposed webs are advanced between a notched, edge-beveled wheel and two beveled anvil surfaces so as to subject the webs to a pair of transversely aligned, intermittent compressive forces.

With this arrangement and technique, relatively light wheel pressures can result in tremendous unit pressures without the problem of deleterious wear which is present in the prior art. On wide machines, in the range of 100 inches to 200 inches web width, with a number of ply-bonding units across the machine width, deflection of the anvil roll has in the past been a very serious factor. As the total load, with the inventive method, is less than about only 1/20, deflection will be reduced by the same factor.

Further, according to the invention, a uniquely presentable or attractive product results. Other advantages of the invention, as well as objectives thereof, can be seen as this specification proceeds.

DETAILED DESCRIPTION OF INVENTION The invention is described in conjunction with an illustrative embodiment in the accompanying drawing, in which:

FIG. 1 is a fragmentary elevational view, partially in cross section, of apparatus incorporating teachings of this invention;

FIG. 2 is an end elevational view of the apparatus of FIG. 1 such as would be seen essentially along the sight line 2-2 applied to FIG. 1;

FIG. 3 is an opposite end (or top) elevational view of the apparatus of FIG. 1, such as would be seen along the sight line 3-3 applied to FIG. 1;

FIG. 4 is an enlarged fragmentary sectional view such as would be seen along the sight line 4-4 applied to FIG. 1;

FIG. 5 is a still further enlarged fragmentary crosssectional view representing an enlargement of the encircled portion designated 5 in FIG. 4;

FIG. 6 is a fragmentary plan view of web materials wherein the plies thereof have been bonded according to the teachings of this invention, with one portion enlarged and encircled and designated 7;

FIG. 7 is a sectional view taken along the sight line 7-7 applied to FIG. 6;

FIG. 8 is an enlarged transverse sectional view seen along the sight line 8-8 applied to FIG. 6;

FIG. 9 is a fragmentary plan view of web material bonded together in accordance with the teachings of the invention and constituting a modification of that seen in FIG. 6; and

FIG. 10 is another fragmentary plan view of the web materials wherein a still further modification of a bonding pattern is provided.

Referring first to FIGS. 1 and 2, the numeral 10 represents a cross shaft which extends between frames (not shown) provided in a web handling machine.

The cross shaft 10 supports a bracket 11 which is fixed to the cross shaft 10. More particularly, the bracket 11 includes parts 12 and 13 bolted together by means of bolts 14 and 15. Thus, it is intended that during operation there is no relative movement of the bracket 11 relative to the cross shaft 10, nor of the cross shaft 10 relative to the frame of the machine.

The bracket 1 1, through parts to be described hereinafter, rotatably supports a notched, edge-beveled wheel 16. The wheel 16 operates in conjunction with a grooved roll 17 to perform the ply bonding on a web 18.

Reference is now made to FIG. 4 wherein fragmentary portions of the wheel 16 and roll 17 are depicted. The roll 17 is advantageously driven (by means not shown), while the wheel 16 can be considered an idler. It will be seen in FIG. 4 that the wheel 16 has beveled edges as at 19 and 20. On the other hand, the roll 17 has a slot 21 defined by insert rings 22 and 23 maintained in spaced apart relation by means of a spacer 24. The outer confronting edges of the plates 22 are beveled, as at 25 and 26, so as to conform to the confronting beveled surfaces 19 and 20 on the bonding wheel 16. It is believed that this can be even more readily appreciated from a consideration of FIG. 5 where the engagement of the beveled surfaces 20 and 26 is shown in further enlarged scale.

This results in a unique bonding of the plies of elongated web material. The sheets, when bonded, have a surface appearance such as that seen in the upper left hand corner of FIG. 6 where two relatively elongated depressions 27 and 28 appear. Also seen in the upper left hand corner of FIG. 6 is a portion of a prior pair of depressions 29 and 30. Interposed between the successive pairs of depressions 27-28 and 29-30 is a relatively undepressed, unbonded area 31. The unbonded area 31 can be seen readily in FIG. 7. The length of the depressions (or compressed areas) 27-30 and the corresponding length dimension of the unbonded area 31 are determined by the character of the teeth 16a (see FIG. 1) on the bonding wheel 16. For example, a wide variety of tooth sizes and spacings may be employed. The number of teeth in a 3-inch diameter wheel may vary from 0 to 70. The spacing 31 may have an arcuate length of 0.02 to .10 inch or more, depending upon the work and apparatus employed. Wheels of this general character have been employed in the past for longitudinal perforating where they operate against hardened anvils and have required special steels because of the high pressures involved. However, according to the invention, this drawback is avoided insofar as the use of relatively exotic materials of construction is concerned.

For apparatus used in bonding tissue and light weight toweling, I have found that a thickness of the spacer 24 of the order of about 0.02 inch is advantageous. In such a case, the angular extent of the beveled surfaces 25 and 26, viz., the dimension A in FIG. 5, is about 0.005 inch. Still further, I find it advantageous to use a wheel wherein the included angle between the beveled edge surfaces, viz., the dimension B in FIG. 4, is from about 45 to about 90 and with the relative angularity of the bevel surfaces 25 and 26 corresponding thereto. With an arrangement with only 14 pounds pressure on the wheel 16 (the means for which to be described hereinafter), and with an included angle B of 60, I develop a large unit force on the web material, i.e., of the order of 50,000 psi. I have found it advantageous to use arrangements whereby the compressive force on each pair of confronting, mating beveled surfaces is of the order of from about 40,000 psi to about 80,000 psi. This results in a glassining which I have attempted to illustrate schematically in FIG. 8. I have found that the web material is not slit or severed, but, however, is compressed to such an extent that it has the translucency characteristic of a glassine heretofore used frequently as bread wrap, etc.

Reference is now made to the first sheet of drawings which includes FIGS. 1-3 for the purpose of explaining one embodiment of a means for loading or applying force to the bonding wheel 16. It will be appreciated that a variety of techniques can be employed for this purpose, particularly in view of the relatively light force that is used herein. However, the instant arrangement does permit adjustment of the bonding wheel relative to the groove (so as to accommodate for wear) without the need for varying the loading on the wheel itself.

In FIGS. 1-3 the numeral 32 designates a wheel holder which is pivotally mounted as at 33 (see the middle portion of FIG. 1) on the bracket 11. For this purpose, a pivot shaft 34 is provided which can also be seen in dotted line in FIG. 2. The wheel 16 is equipped with a ball bearing 35 (see the extreme middle left hand side of FIG. 2) which permits it to rotate freely relative to the fixed shaft 36. It will be noted that the shaft 36 is fixed within the bracket 32 by means of a set screw 37 and that the fixed shaft 36 has an enlarged end as at 38 to confine the bonding wheel 16 in position. The bonding wheel is seen to be offset from the enter line of the bracket 11, and this is advantageous because an opposite hand unit can be installed immediately adjacent the one pictured in FIG. 2 so as to give relatively closely spaced lines of longitudinal bonding.

The wheel holder 32 is bifurcated as at 39 (see FIG. 2) to provide a pair of integral lug portions 40 and 41 (see FIG. 3). The bracket 11 is likewise bifurcated to provide a pair of integral lug portions 42 and 43.

I install a pin 44 through aligned openings in the lug portions 40 and 41. In like fashion I install a pin 45 through aligned openings in the lug portions 42 and 43 provided on the bracket 1 1. Each pin 44 and 45 in turn is equipped with a transverse opening so as to accommodate receipt of a cap screw 46. The cap screw 46 is threaded at its end 46a, and is threadedly received within the bore provided in the pin 44. On the other hand, the transverse bore or opening in the pin 45 provides a clearance for the shank of the cap screw 46.

A nut 47 is threadably received on the cap screw 46, and provides a stop for a coil spring 48. The other stop is provided by the pin 45.

It will be appreciated that turning the cap screw will change the position of the pin 44 relative to the length of the cap screw, and thus will move the wheel 16 relative to the anvil roll 17 by pivoting around the point 33. This occurs without any change in the pressure of the wheel 16 relative to the beveled surfaces 25 and 26. To increase the pressure, the lock nut 47 is repositioned, changing the length of the spring 48.

It will be appreciated that a small air cylinder or like means may be used in place of the cap screw 46, spring 48, and nut 47 so as to do away with the adjustment of the cap screw 46 and lend itself to remote control when desired.

In the practice of the invention, a 99-inch wide rewinder for two-ply toilet tissue requires 44 of the assemblies, viz., the bracket 11, wheel 16, etc. In such a case, the ply bond units may be engaged only just before and after cutoff and for only a few feet. This makes the transfer to the new core easier, and prevents the user from unwinding the wrong plies at the beginning of a new roll. When the latter happens, the perforations do not match between the plies, and the user can get very upset.

For toweling and other two, three, or four-ply products, where relatively large areas are involved, it may be desirable to have continuous ply bonding along the two edges, and intermittent, short, ply bonding in whatever pattern desired over the rest of the surface. This is illustrated in FIG. 10. Any intermittent ply bonding may be accomplished by pivoting the shaft 10 or through cam actuating means against a variation of cap screw 46, or by air as mentioned above by simply pulsing the pressure between 0 and 14 lbs. In this connection, it will be appreciated that bonding across lines of perforation may be achieved as illustrated in FIG. 9.

Many variations of the ply bonding patterns are possible. The distance between the two lines may be increased from the form illustrated viz., about 0.020 inch to 1 inch or more. Further, the notches may be at an angle. It is also possible to have two ply bonding wheels with a spacer in between with the notches staggered if desired. In this case, only the outer surfaces of the two wheels would be used. Further, it is also possible not to have any notches in the ply bonding wheel, but instead, the anvils may be notched. This, however, is more expensive and is not preferred. Also, both the wheel and anvils could be notched, but no real advantage is seen to this approach, even if the ply bonding wheel would be driven in order to match or mismatch the notches. It would appear that the end result would only be more expensive.

Most multi-ply paper articles, such as facial tissue, toilet paper, handkerchiefs, napkins, toweling, place mats, table covers, industrial wipes, etc., may be greatly improved by the use of the ply bonding method. Its low cost, high speed capability, ease of operating, and low maintenance makes it ideal, and fills a real need in the industry.

While in the foregoing specification a detailed description of an embodiment of the invention has been set down for the purpose of illustration, many variations in the details herein given may be made by those skilled in the art without departing from the spirit and scope of the invention.

I claim:

1. In a method of ply-bonding of elongated superposed webs, the step of advancing said webs between edge-beveled wheel means and two beveled anvil surfaces to subject said webs to a pair of transverselyspaced convergently related compressive forces only along lines parallel to the direction of web advance.

5. in a method of ply-bonding of elongated superposed flexible webs, the steps of advancing said webs while simultaneously therewith applying to said webs a pair of transversely-spaced, convergently-related compressive forces only along lines parallel to the direction of web advance. 

1. In a method of ply-bonding of elongated superposed webs, the step of advancing said webs between edge-beveled wheel means and two beveled anvil surfaces to subject said webs to a pair of transversely-spaced convergently related compressive forces only along lines parallel to the direction of web advance.
 2. The method of claim 1 in which at least one of said wheel means and anvil surfaces is notched.
 3. The method of claim 1 in which the included angle between the beveled surfaces is from about 45* to about 90*.
 4. The method of claim 1 in which each compressive force is of the order of about 40,000 psi to about 80,000 psi.
 5. In a method of ply-bonding of elongated superposed flexible webs, the steps of advancing said webs while simultaneously therewith applying to said webs a pair of transversely-spaced, convergently-related compressive forces only along lines parallel to the direction of web advance. 